Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5e74f882671f012f…

MALICIOUS

RTF / .DOC

1.24 MB
MD5: 4653666f00c5fcaea999e2b2450d92c9 SHA-1: 8162a3d080fa2ed67d2d3c47e492dd2cf66c0434 SHA-256: 5e74f882671f012f207611f8b87f0a90336f0df22416427e20c2a843a2d69d8a
222 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF document contains embedded OLE object data, specifically related to Equation Editor, which is indicative of the CVE-2017-11882 vulnerability. This vulnerability is known to be exploited for client execution by allowing the execution of arbitrary code. The presence of a large, high-entropy OLE object suggests it contains a decoded payload.

Heuristics 6

  • Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED
    RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact attribution was not recovered.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1296KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \objdata section(s) — embedded OLE objects
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000000a2.bin
ef332278999e86af27d6d8161655e01d2143f1e718d416f5958dc2790489e48b
rtf-objdata-decoded RTF \objdata at offset 0xA2 648133 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 7.99, consistent with packed or encrypted content.